package com.tjb.reggie.controller;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import com.tjb.reggie.common.R;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

/**
 * @author tjb
 * @version 1.0
 * @date 2022/8/25 14:45
 */
@RestController
@RequestMapping("/common")
public class CommonController {
    @Value("${reggie.file.path}")
    public String path;
    @PostMapping("upload")
    public R<String> upload(MultipartFile file){
        //file十一临时的文件，需要转存到指定位置，否则本次请求完成后临时文件会删除
        //原始文件名
        String originalFilename = file.getOriginalFilename();
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用UUID重新生成文件名，防止文件名称重复造成文件覆盖
        String fileName = UUID.randomUUID().toString().replace("-","").concat(suffix);
        File dir = new File(path);
        if (!dir.exists()){
            //目录不存在，进行创建
            dir.mkdir();
        }
        try {
            //将临时文件转存到指定位置
            file.transferTo(new File(path + fileName));
        }catch (IOException exception){
            exception.printStackTrace();
        }
        return R.success(fileName);
    }
    @GetMapping("download")
    public void download(String name, HttpServletResponse response) throws IOException {
        //输入流，通过输入流读取文件内容
        FileInputStream fileInputStream = new FileInputStream(new File(path + name));
        //输出流，通过输出流将文件写回浏览器，在浏览器展示图片了
        ServletOutputStream outputStream = response.getOutputStream();
        response.setContentType("image/jpeg");
        int len = 0;
        byte[] bytes = new byte[1024];
        while ((len = fileInputStream.read(bytes)) != -1){
            outputStream.write(bytes, 0, len);
            outputStream.flush();
        }
        //关闭资源
        outputStream.close();
        fileInputStream.close();
    }
}
